As with most of my walkthroughs I've concentrated on the puzzles, providing detailed explanations of the clues, logic and reasoning required to solve them. The more straightforward actions are only included for sake of completeness.

GENERAL TIPS

Many of the puzzles are inventory based, so always look around carefully and pick up everything you find. There are a number of objects (with hotspots) that can only be used or taken after doing something else, or if you have the correct item to interact with it. Make a note of these as they will be used or needed later in the game.

Certain inventory items may need to be combined or worked on. This is always done on one of the many 'combining rocks' you find everywhere.

Check the documentary database and Arok's journal regularly, they often contain clues. The 'shell' and 'hand' symbols will briefly flash in the top right corner when the database or journal contain new entries.

Save your game position often, especially before trying to solve puzzles. Although most of the puzzles can be reset to their original state, there are a few that can't and you may want to restore to a position before these puzzles.